Heard a loud droning sound, thought it was a helicopter at first though the sound wasn't quite right. After about five minutes checked the windows to see if I could see what was making the sound. I saw lights in a triangle shape three with red blinking and two green/blue in the same area as the red. It moved very slowly Westward. The droning was constant and very loud. It seemed to almost be hoving at times and took approximately 15 min to disappear from sight towards the mountains.